The present invention relates generally to solar panels with adjustable supports, and more particularly, to solar panels for electrically powering devices such as portable signage and having adjustable mounting supports for optimally orienting the solar panel relative to the sun.
Portable signs are used in a variety of applications such as roadside traffic control and message signs and commercial advertising. Such roadside traffic signs are commonly used to identify and designate vehicle lanes and entry and exit ramps, to provide other traffic control information, and to alert drivers of traffic conditions, construction sites, and other important road conditions.
Roadside signs are commonly mounted on a trailer frame that allows the sign to be towed by a vehicle to different locations. To provide sufficient sign illumination at night and during low sunlight daytime periods, portable roadside signs commonly have a portable rechargeable battery and a generator or a solar panel for recharging the battery during daylight. The solar panels typically comprise an array of operatively connected photovoltaic cells that produce a voltage and transmit an electrical current to the battery and/or sign for operation thereof.
In order for the solar panel to receive as much solar energy as possible for conversion into electricity, it is desirable to mount the solar panel on an adjustable support apparatus that allows for variably orienting the solar panel relative to the general position of the sun. For example, when a portable sign is moved to a new location in the Northern hemisphere, the solar panel should be adjusted to face a Southerly direction while allowing the sign to face the desired target audience.
There are known in the art a number of solar panels and mounting assemblies for a variety of applications that provide for orienting the solar panel toward the sun. For the purpose of clarity herein, xe2x80x9ctiltingxe2x80x9d is defined as pivotal movement about a horizontal axis thereby forming a declination angle, and xe2x80x9crotatingxe2x80x9d is defined as rotational movement about a vertical axis thereby forming an azimuthal angle.
U.S. Pat. No. 4,421,943 to Withjack discloses a collapsible mobile solar energy power source comprising solar panels mounted on a towable trailer. Each solar panel is pivotally attached at its bottom edge to a main base, and a variable support leg assembly is provided for tilting the solar panel to a storage position inside the base. The Withjack device is thus capable of tilting, but not rotating, to track the sun.
U.S. Pat. No. 5,228,924 to Barker et al. discloses a photovoltaic panel support assembly comprising photovoltaic panels supported for pivotal movement on a horizontal axis, with a motor drive and telescoping tubes for extending to pivot the panel. The Barker et al. device is thus capable of tilting, but not rotating, to track the sun.
U.S. Pat. No. 5,379,753 to Noennich discloses a solar panel control apparatus comprising a solar panel with weights on one end for tilting that end downward. A crank mechanism is connected to the center of the solar panel for raising or lowering the panel. The Noennich device is thus capable of tilting, but not rotating, to track the sun.
U.S. Pat. No. 4,129,360 to Deflandre et al. discloses heliostats comprising a mirrored panel for reflecting solar energy onto a solar panel. Three tubes are arranged in a triangular configuration forming a base, with the panel bottom edge pivotally attached to base and a variable length bar attached to the base and the panel top edge for tilting the mirror panel. A curved track is provided for rotating the mirror panel. The Deflandre et al. device thus provides for tilting and rotating the mirror panel to orient the mirror panel towards the sun.
U.S. Pat. No. 4,771,764 to Cluff discloses solar collectors on a raft floating in water. The bottom of each solar collector is hingedly mounted to the raft and the top of each is pivotally connected to a push-pull rod for tilting to provide for tracking of the sun. A roller engages and rotationally drives a side of the raft as it floats in the water. The Cluff device thus provides for tilting and rotating the solar collectors to orient them towards the sun.
U.S. Pat. No. 5,022,929 to Gallois-Montbrun discloses a solar collector comprising a plurality of solar panels each having a front and rear panel hingedly connected together. Each rear panel is tiltable relative to the corresponding front panel by a hydraulic jack attached to two links attached to the panel. The solar collector is mounted on a rotatable plate. The Gallois-Montbrun device thus provides for tilting and rotating the solar collector to orient it towards the sun.
U.S. Pat. No. 5,542,203 to Lumoa et al. discloses a mobile sign mounted on a trailer frame. A solar panel is mounted to the sign by a mast having a stationary lower portion mounted to the trailer frame and a telescopically extendable upper portion connected to the solar panel. Pivotal linkages are attached to the mast and the solar panel for tilting the panel. The mast is rotatable for rotating the solar panel. The Lumoa et al. device thus provides for tilting and rotating t he solar collector to orient it towards the sun.
Each of these prior art devices generally provides for tilting and rotation of the panel. Titling of the panel is generally provided by a pivotal connection at the bottom of the panel and a drive mechanism of some sort, with the panel bottom either directly hinged to a base of some sort or hingedly connected to a rigid non-extendable linkage. Several of these devices also provide for rotation of the panel, however, such rotation is independently provided by separately rotating the support apparatus (such as a pole or plate) for the entire panel, thereby requiring an additional drive mechanism to accomplish rotation in addition to tilting.
U.S. Pat. No. 5,600,124 to Berger discloses a solar panel mounted on a pole, with two cross-bars pivotally attached to the pole and the solar panel for tilting the solar panel, and two or four cylinders are connected to the pole for tilting or rotating the panel. To provide for additional rotation of the solar panel, the pole is rotary. The Berger device thus provides for tilting and rotating the solar collector to orient it towards the sun.
In order for the cylinders to provide the rotation function, however, the device provides complex diversion valving operable in conjunction with a radial catch that is believed to allow the solar panel only one axis of turning at a time and a limited rotational turning angle, and that makes the device generally more costly and less reliable. Thus, while Berger provides for rotation of the solar panel by means in addition to rotating the support pole, the mechanisms for accomplishing such rotational have not proven entirely satisfactory.
Accordingly, what is needed but not found in the prior art is an adjustable solar panel which can be used for electrically powering devices such as portable signage, and that has adjustable mounting supports for optimally orienting the solar panel at any angle relative to the sun by simple, reliable, cost-effective means.
The present invention provides an apparatus for enabling a solar panel to track a solar or other energy source, comprising a panel; a mast; a first collar slidingly receiving the mast; a sleeve slidingly receiving the mast and the link tube; a controller second collar slidingly receiving the mast; a universal joint comprising a first section and a second section, both sections pivotably joined, the first section fixedly attached to one end of the mast; a first arm fixedly attached to the controller second collar; a second arm fixed attached to the first collar; a link pivotably joining the first arm and the second arm; a first stop associated with the first collar; wherein the mast is capable of vertical movement within the first collar such that the panel can tilt and be displaced angularly.